1. Field of the Invention
The present invention relates to a high power semiconductor light source and a method of manufacturing the same, and more particularly, to a superluminescent diode (SLD) which emits light of 1.55 μm wavelength, and a method of manufacturing the same.
2. Description of the Related Art
Conventional light sources for optical communication, optical measurement and bio-imaging generally emit visible light or light of 1.3 μm wavelength. There has been very little research into a superluminescent diode (SLD) which emits light of 1.55 μm wavelength, until now.
Conventional structures for suppressing laser oscillation of an SLD include: i) an inclined resonating axis; ii) an optical absorption layer formed by ion implantation; and iii) a window structure without an active layer. Important variables of an SLD are its optical power, spectrum width, and modulation depth. An SLD generating an optical power greater than 100 mW receives an injection current of several amperes and has an optical power waveguide having a width of several tens of μm, which is much wider than a waveguide used in a communication device. For example, the width of the waveguide for a communication device is about 2 to 3 μm. Since an injection current of less than 200 mA is supplied to SLDs for optical communication and bio-imaging, these SLDs cannot generate an optical power greater than 20 mW.
Therefore, there is a demand for an SLD generating an optical power greater than 20 mW and having an optical power spectrum wider than 20 nm to provide broadband characteristics.